Shoe sole and heel

ABSTRACT

A shoe sole and heel integrally molded of an elastomeric material having a filler of hollow glass spheres dispersed therein. The spheres are mixed with the elastomeric material prior to molding. The resulting composition is injection molded in the shape of a heel and sole directly on the bottom of a shoe upper to form a lightweight, relatively inexpensive and wearresistant shoe bottom.

nited States Patent [191 Egtvedt [4 1 Feb. 12, 1974 SHOE soLE AND HEEL[75] Inventor: Robert B. Egtvedt, Comstock Park,

Mich.

[73] Assignee: Wolverine World Wide, lnc.,

Rachford, Mich.

221 Filed: Jan. 19, 1972 21 Appl. No.: 219,031

[52] US. Cl. 36/28, 36/32 R [51] Int. Cl A431) 13/18 [58] Field ofSearch 36/28, 32 R [56] References Cited UNITED STATES PATENTS 2,766,80010/1956 Rockoff 36/32 R UX 2,374,487 4/1945 Jayne 36/32 R 2,651,1189/1953 Root 36/32 R 2,757,461 8/1956 Cartmell 36/59 C X 3,046,172 7/1962Reid 161/160 [1X 3,219,600 11/1965 Rucker 161/D1G. 5 3,515,625 6/1970Sedlak et al. l6l/D1G. 5 3,596,381 8/1971 Fukuoka 36/32 R X PrimaryExaminer-Alfred R. Guest Attorney, Agent, or Firm--Price, Heneveld,Huizenga & Cooper [5 7] ABSTRACT A shoe sole and heel integrally moldedof an elastomeric material having a filler of hollow glass spheresdispersed therein. The spheres are mixed with the elastomeric materialprior to molding. The resulting composition is injection molded in theshape of a heel and sole directly on the bottom of a shoe upper to forma lightweight, relatively inexpensive and wearresistant shoe bottom.

9 Claims, 2 Drawing Figures Patented Feb. 12, 1974 SOURCE or HOLLOWSPHERES 52 2 I I 2 SOURCE OF MIXING INJECTION LIQUID STAGE MOLDINGELASTOMERIC APARATUS MAT'L 1 SHOE SOLE AND HEEL BACKGROUND OF THEINVENTION The present invention relates to shoe soles and heels and morespecifically, to a shoe sole and heel molded of an elastomeric materialincluding a filler of hollow glass spheres.

Shoe sole material molded entirely of an elastomeric material such aspolyvinyl chloride (PVC) is relatively expensive due to the cost of thematerial, as well as being heavy, due to the density of the PVCemployed. Additionally, a sole and heel made of a pure elastomericmaterial does not have wear-resistant properties as good as compositionsole and heel materials.

Shoe soles and heels have been molded of an elastomeric material havinguniform gas bubbles dispersed within the material to reduce the cost ofthe material as well as reducing the weight of the shoe. The matricesformed with the gas bubbles within the sole material, however, areprimarily for the purpose of increasing the elasticity of the shoebottoms and do not increase the wear-resistance of the material. Thewearresistance of the shoe sole and heel so formed is actually reduced;U. S. Pat. Nos. 3,005,272, Shelare, et al., issued on Oct. 24, 1961 and3,552,039, Fukuoka, issued on Jan 5, 1971, describe shoe soles and heelsso formed.

U. S. Pat. No. 3,046,172, J. S. Reid, issued on July 24, 1962, suggeststhe use of hollow clay spheres within an elastomeric material for themanufacture of the shoe sole material. This patent, however, teaches thestep of crushing the spheres after the molding process to form gas voidsdirectly within the shoe sole material thereby increasing itselasticity. Such a process is directed primarily to forming an elastic,compressible material and not a process or material for increasing thewearresistance properties of the shoe material. The process of thepatent eliminates the difficulties of dispersing small gas bubbleswithin the binding material to achieve the same purpose as described inthe Shelare, et al., and Fukuoka patents, supra.

SUMMARY OF THE INVENTION The shoe sole and heel material of the presentinvention, employs a filler of hollow glass. spheres mixed within anelastomeric material such that the spheres remain intact to providerigidity to the shoe sole material as well as wear-resistance at thesurface of the material. The integrally molded shoe sole and heel soformed can be molded directly to a shoe bottom as by using an adhesiveto insure the molded shoe sole and heel will adhere securely to thebottom of the shoe.

It is an object of the present invention to provide shoe sole and heelmaterial which is lightweight, relatively inexpensive, andwear-resistant.

It is an additional object of the present invention to provide a shoesole material having a filler of hollow spheres that can be moldeddirectly to a bottom of a shoe during the manufacturing of the shoe.

It is still an additional object of the present invention to provide animproved shoe sole and heel material comprising an elastomeric materialhaving uniformly dispersed hollow glass spheres within the material toreduce the weight of the shoe sole and heel material as well asincreasing the wear-resistant properties of the resulting shoe sole andheel so formed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cut-awayperspective view of a shoe having a sole and heel embodying the presentinvention; and

FIG. 2 is a block diagram of the process employed to manufacture theshoe sole and heel material shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detailto FIG. 1 there is shown a shoe 10 having an upper portion 12 made of aleather material such as pigskin. Edges l3 and 15 of the upper materialare inwardly turned around an innersole 16 and cemented to the innersoleduring the manufacturing process.

Attached to the bottom of the innersole 16 is an integrally formed shoesole 20 and heel 22. The sole 20 and heel 22 can be integrally molded asshown in FIG. 1 or can be separately molded and attached to the shoe 10.

Also the shoe 10 may include only a sole portion 20 made according tothepresent invention and use a conventional rubber or composition heel 22which is later attached to the shoe 10. Also, the shoe sole and heel 20,22 embodying the present invention can be employed with a variety ofshoes and boots having designs different than that illustrated in FIG.1.

The manufacture of the sole and heel 20, 22 is illustrated by the blockdiagram of FIG. 2 which shows that a source 26 of liquid elastomericmaterial (FIG. 1) such as PVC supplies the liquified elastomericmaterial to a mixing stage 28 which includes a suitable mixing vessel.The mixing stage 28 is also supplied with hollow glass spheres 30(FIG. 1) from a source 32 of such glass spheres. These spheres can rangein diameter from 25-l00 micrometers and are commercially available fromthe Minnesota Mining and Manufacturing Company. Spheres of micrometerdiameter were used in the preferred embodiment.

The mixing stage 28 combines the glass spheres 30 with the PVC binder 25in a mixture of 15-20 percent spheres to -80 percent PVC by volume. Thevolumetric ratio of spheres to binder can vary somewhat although therange of 15-20 percent provided the best results. A uniform mixture isachieved by well known processes as exemplified in U. S. Pat. No. 3,046,172.referred'to above. After mixing the liquified PVC and glassspheres, the mixture is fed to an injection molding apparatus 40 havinga plurality of molds (not shown) shaped in the form of the sole and heel20, 22 illustrated in FIG. 1. The molds are mounted adjacent theinnersole 16 of the shoe 10 such that the molded shoe sole 20 and heel22 can be directly bonded to the bottom of the shoe 10. A neoprenebinder, applied to the outer edges 13 and 15 of the upper material 12prior to the application of the sole and heel insures adhesion. It ispossible, of course, to mold the integral shoe sole and heel 20 and 22and later cement it to the bottom of the shoe 10. Likewise, it isequally possible to mold the sole and heels separately for lateradhesion to the shoe bottom.

Various elastomeric materials which can be liquified for mixing thesphers within the material can be used as the shoe sole and heelmaterial. Such elastomeric materials include styrene-butadiene rubber(SBR), polyurethane, and. other well known materials. Al-

though glass spheres have been successfully employed in the preferredembodiment, spheres of materials such as ceramic, epoxy, polyesterresin, or Saran" can likewise be successfully employed. It is important,however, that the spheres remain intact such that the shoe sole materialmaintains its rigidity and wear-resistant properties.

Other variations of the present invention falling within the scope ofthe present invention as defined by the appended claims will becomeapparent to those skilled in the art.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows.

1. A shoe sole molded of an elastomeric material having a rigid fillermaterial comprising intact hollow spheres dispersed uniformly therein,said spheres being of lesser density than said elastomeric material andforming approximately 15-20 percent by volume of the sole.

2. The shoe sole as defined in claim 1 wherein said spheres comprisehollow glass spheres having a diameter of from 25 to 100 micrometers.

3. The shoe sole as defined in claim 1 wherein said elastomeric materialis polyvinyl chloride.

4. The shoe sole as defined in claim 1 and further including anintegrally molded heel.

5. In a shoe sole molded of an elastomeric material, the improvementcomprising a rigid filler of uniformly dispersed hollow spheres withinsaid elastomeric sole material and comprising 15-20 percent of the totalvolume of said shoe sole.

6. The shoe sole as defined in claim 5 wherein said filler comprises 15to 20 percent of the total volume of said shoe sole.

7. A shoe having an innersole with a bottom attached thereto, saidbottom comprising a heel and sole integrally molded from an elastomericmaterial and including a plurality of hollow glass spheres uniformlydispersed therein, said sphers having a diameter of from 25 tomicrometers and comprising 15 to 20 percent by volume of said bottom.

8. The shoe as defined in claim 7 wherein said elastomeric materialcomprises PVC.

9. The shoe as defined in claim 8 wherein said bottom is molded directlyto said innersole of said shoe.

1. A shoe sole molded of an elastomeric material having a rigid fillermaterial comprising intact hollow spheres dispersed uniformly therein,said spheres being of lesser density than said elastomeric material andforming approximately 15-20 percent by volume of the sole.
 2. The shoesole as defined in claim 1 wherein said spheres comprise hollow glassspheres having a diameter of from 25 to 100 micrometers.
 3. The shoesole as defined in claim 1 wherein said elastomeric material ispolyvinyl chloride.
 4. The shoe sole as defined in claim 1 and furtherincluding an integrally molded heel.
 5. In a shoe sole molded of anelastomeric material, the improvement comprising a rigid filler ofuniformly dispersed hollow spheres within said elastomeric sole materialand comprising 15-20 percent of the total volume of said shoe sole. 6.The shoe sole as defined in claim 5 wherein said filler comprises 15 to20 percent of the total volume of said shoe sole.
 7. A shoe having aninnersole with a bottom attached thereto, said bottom comprising a heeland sole integrally molded from an elastomeric material and including aplurality of hollow glass spheres uniformly dispersed therein, saidsphers having a diameter of from 25 to 100 micrometers and comprising 15to 20 percent by volume of said bottom.
 8. The shoe as defined in claim7 wherein said elastomeric material comprises PVC.
 9. The shoe asdefined in claim 8 wherein said bottom is molded directly to saidinnersole of said shoe.